I'm using the amazing Morroblivion .64 and have been able to use the ships to travel back and forth. Is there a mod to allow traveling via foot and swimming? When I tried, fell into a giant hole/end of the world sort of thing. So, I might not have turned all the borders off, correctly.

Morroblivion is a totally separate worldspace (just like the Shivering Isles) from Cyrodiil. The only way to get there is by ship. IIRC, somebody tried merging the Morrowind worldspace with the rest of the Tamriel heightmaps years ago, but the result wasn't ideal. Simply put, there's just so damn much going on in Morrowind that to try to make it occupy the same worldspace is unfeasible. Your game would probably crash a lot just from the sheer amount of stuff it would need to keep track of.

Somebody DID make a "workaround" mod that telports you to the corresponding coordinates in Morrowind when you walk there in the Tamriel worldspace. So you would cross the borders over into Morrowind and when you make it to the island of Vvardenfell, you would hit a loading screen and would appear in that corresponding location in Vvardenfell. Honestly, it's such a roundabout way of doing it that it breaks immersion and wouldn't be worth it, in my opinion. You still see the vanilla, lo-res landscapes in the distance until you hit the point where it teleports you to the Morrowind worldspace.

Thanks for your reply. No hurry, at your convenince could you share the name of the mod? I don't mind a workaround, in a sense it's the same thing the ships do, nor do I mind a loading screen. I would almost worry if someone did try to merge the two world spaces together, mostly due to stability. I've got Epona, a mod from Slof Horses package, which is a mount that can waterwalk.